VLA to investigate PCV2 as a cause of reproductive failure

The Veterinary Laboratories Agency (VLA) is to increase surveillance for PCV2 virus as a cause of reproductive failure in cases of abortion and stillbirth where no other infectious cause has been identified.

The hearts of stillborn or aborted piglets submitted to the agency will be examined for myocarditis, the lesion caused by PCV2 in the heart of the developing pig foetus. When a myocarditis is detected, immunohistochemistry will be used to determine whether PCV2 is the cause.

Susanna Williamson is a Veterinary Investigation Officer with the VLA. She says: “In cases of abortion and stillbirth in piglets, we have always looked for a variety of causes, but checking for myocarditis, which can be associated with PCV2 was not always included. Data from the field and research show that PCV2 can be transmitted to the pig foetus, and may, in previously naïve gilts and sows, cause piglets to be aborted or stillborn with myocarditis lesions.

“Through this increased surveillance we will be able to monitor for PCV2-associated abortion and stillbirth and obtain a better idea of the role that it plays in porcine reproductive failure in England and Wales. To date, we have not diagnosed PCV2 as a cause of reproductive failure. Other pathogens may also cause myocarditis, which is why it will be essential to demonstrate the PCV2 in association with lesions to obtain a diagnosis.”

PCV2 virus effectRicardo Neto, Veterinary Advisor with Merial Animal Health said: “We welcome this move as it should provide a clearer picture about what is happening with regard to the transmission of the PCV2 virus and the effect that it has. We have clear evidence from studies in the UK that vaccinating sows against PCV2 benefits reproduction, including increasing the number of piglets born alive and weaned per litter. It would be very helpful if vets could have a diagnosis of PCV2 in reproductive failures on their client farms, especially because the control of PCV2 among breeding animals can have such a great economic impact.

“These results could also give us a better understanding of the transmission mechanism and, therefore, the importance of vaccinating sows and gilts.”

Susanna encourages vets to submit aborted and stillborn piglets in the case of unexplained problems. She said: “Understandably, we tend to get submissions where there are outbreaks of abortions and stillbirths, as these are more likely to be associated with infectious disease. However, submission of abortions and stillbirths from sporadic cases or where there are more chronic problems can also be useful in investigating whether certain infectious diseases are playing a role – PRRSV and PCV2, in particular.”